4 patents making innovative use of silicones and alternatives

The following cosmetic patents are built on silicones or their feel-good alternatives

This month’s patents make innovative use of silicones and/or their alternatives to achieve everything from illusionary soft-focus effects in facial make-up to high-shine lip gloss.

The patents include cosmetics based on hydrophobic silica aerogel particles that are soft on application; a viscous silicone material to disguise blemishes; a luminising emulsion containing bismuth oxychloride; and a high-gloss gel lipstick.

1. Cosmetic composition comprising silica aerogel particles and silicone oils
US Patent 9,956,434
Application No 13/995,773
Granted 1 May 2018
Assignee L’Oréal

The patent describes a cosmetic comprising a mixture of hydrophobic silica aerogel particles and at least three linear silicone oils to obtain compositions that are comfortable and soft on application, and have mattifying and soft-focus properties.

The preferred aerogel particles are hydrophobic silica aerogels surface-modified with trimethylsilyl groups to provide silyl silica (INCI: Silica silylate).

A preferred average particle size is about 1,000mm and a specific surface area per unit of mass ranges from 600- 800mm2/g.

Ideally, they represent between 6% and 8% by weight of the aerogel/silicone oil mixture and 0.5-2% by weight relative to the total weight of the final composition.

The linear silicone oils are commonly known as dimethicones and three different ones are included in the patented composition.

They differ in their viscosity with two being less than 15mm2/s and the third having a viscosity between 300mm2/s and 500mm2/s when measured according to standard ASTM D-445 at 25°C.

The more viscous dimethicone is present at preferably from 1-5%w/w and the less viscous dimethicones may each represent from 40-50%w/w, relative to the total weight of the mixture of silicone oils.

The mixture of aerogel particles and silicone oils may be incorporated in an o/w emulsion or aqueous gel at between 5% and 10% by weight, and used in cosmetic compositions such as make-up products that, when applied to the skin, provide a matte, soft-focus deposit.

2. Methods for disguising dermatological blemishes
US Patent 9,186,315
Application No 13/444,426
Granted 17 November 2015
Assignee Silicone Arts Laboratories

Cosmetic compositions are well-known as a means of enhancing or otherwise altering a person's appearance and may be used to cover inconsistent skin pigmentation and wrinkles.

However, standard cosmetics are not always suitable where the skin defect is significant because of trauma or severe acne scarring.

The patent describes methods for disguising dermatological blemishes by providing a package containing a viscous silicone material, a cosmetic pigment and a catalyst.

The package may also include double-barrel syringes holding the viscous silicone material and the catalyst, separately.

The method includes applying the silicone mixture and allowing the silicone material to cure on the skin surface of the user.

The first composition comprises a silicone material tinted to match a selected skin tone and a flocking agent dispersed therein to provide texture.

The flocking agent can be natural hair or natural or synthetic fibres and the silicone material further comprises a thixotropic thickener for suspending the flocking agent.

Colloidal silica is claimed to be suitable. The silicone may be any that is capable of polymerisation by catalysis at room temperature; particularly mentioned are polydimethylsiloxanes.

The second syringe contains a catalyst to react with the viscous silicone material, which cures as a translucent elastic layer bonded to the skin. A platinum catalyst is preferred.

One particularly desired combination of silicone material and catalyst is NuSil MED2-4220 available from NuSil Technology.

It is provided as a two-part translucent silicone elastomer system that cures at room temperature. To these materials may be added pigments surface treated with silicone, the flocking agent and a diluent oil.

3. Emulsion containing a dispersion of bismuth oxychloride
US Patent 9,956,147
Application No 15/217,527
Granted 1 May 2018
Assignee L’Oréal

The inventors studied the impact of visible light on the skin: 5% of the radiation is directly reflected, reflecting the entire colour spectrum.

This is the surface radiance, whereas 95% penetrates the skin, interacting with the epidermis and the dermis, and 40% is re-diffused at the surface. This is the light inside the skin.

The patentees sought to maintain skin radiance in more mature skin and described is a cosmetic emulsion for topical application that imparts a luminous effect to the complexion.

A dispersion is prepared that contains 68-72% by weight of bismuth oxychloride in 28-32%w/w of ethylhexyl hydroxystearate.

This is mixed with phenyl trimethicone and the final composition contains up to 15%w/w of the dispersion with phenyl trimethicone, however the preferred level is 2-3%.

The emulsion also contains at least one hydrocarbon-based oil with a refractive index of 1.45 or above and (of the many mentioned) hydrogenated castor oil/sebacic acid copolymer is preferred.

The aqueous phase is preferably 50-60% of the total composition and approximately 15% of the aqueous phase should be ethanol.

An emulsifier is required and 2-3% of cetyl dimethicone copolyol is said to be suitable.

The composition may contain fillers and binders, viscosity control agents, pigments, colourants and preservatives, and other materials that improve the stability and aesthetics of the product.

Mention is made of calcium carbonate as a suitable filler and preferably a soft-focus agent is chosen from a sericite/TiO2/ brown iron oxide/silica composite pigment, a polyurethane powder or a silicone elastomer and mixtures thereof.

4. High gloss gel-based lipstick
US Patent 7,989,002
Application No 11/642,348
Granted 2 August 2011
Assignee Avon Products

Described are cosmetic compositions for imparting high gloss to the lips and for imparting films on the lips with enhanced slip and feel.

Claimed are gel-based lipstick compositions comprising an ester terminated poly(esteramide) (ETPEA) polymeric gellant, waxes, oils and a silicone resin.

The gel compositions are solid or semisolid at room temperature and are capable of being moulded into self-supporting sticks.

The gels provide high gloss films when applied to the lips and provide a rheology characterised by a high viscosity over repeated shear cycles.

The ETPEA is capable of gelling low-polarity and non-polar oils and preferred is bis-stearyl ethylenediamine/ neopentyl glycol/stearyl hydrogenated dimer dilinoleate copolymer with an average molecular weight between about 3,000 and 7,500 Daltons, incorporated at between 0.1-12% by weight relative to the total weight of the composition.

The preferred waxes, which in combination comprise from 5-40% of the composition are a microcrystalline petroleum wax, ozokerite and a linear polyethylene wax. The preferred silicone resin is phenyl propyl polysilsesquioxane resin present at 5-10%w/w.

The combination of gelled matrix with high and low melting point waxes contributes a rheology characterised by a slip and feel normally only associated with liquid lip products.

In addition, the gel network is inherently transparent and thus the gloss of the oily components is not compromised.

The low-polarity or non-polar oils are selected from the group consisting of esters, hydrocarbons and silicone-based oils.

Many are listed but preferred are diphenyl dimethicone, perfluorononyl dimethicone and phenyl trimethicone because of their good organic compatibility and film-forming characteristics.

Isohexadecane, isoeicosan, and isododecane and various esters like C12-15 alkyl benzoate and triisostearyl trilinoleate may be included.

The compositions optionally contain mica as a pearling agent, various fillers, film-formers, pigments and flavourings.

Table 1 features a formula for a lipstick from the patent.

Table 1
